Wind turbines are arranged to convert energy contained in flowing wind to electrical energy. Because of technological constraints, the size of individual wind turbines is still limited to a few or several megawatts. Therefore, wind turbines may be brought together in wind power plants, also referred to as wind farms or wind parks. A wind power plant typically consists of tens to hundreds of wind turbines arranged to run simultaneously. The wind turbines are electrically connected in a collector grid (typically underground cables). The wind turbines and the collector system is connected to the transmission or distribution grid at a single point, referred to as the point of common connection (PCC) of the particular wind power plant. With the increase in penetration of wind power in power systems, the dynamic influence of a large wind power plant on power systems is becoming an issue for integration and operation of wind power plants. Therefore it is important to be able to calculate the electrical output from wind power plants.
The dynamic behavior of a wind power plant may be represented by a detailed model in which the dynamics of each individual wind turbine and the internal electrical network are fully represented. However, since a large wind power plant typically comprises a large number of wind turbines, such a detailed model requires excessive computational time in order to determine the electrical output from the wind power plant. It is thus a problem of such a detailed model, that it is not suitable for studying the impact of the entire wind power plant on the dynamic behavior of a large-scale power system. To reduce the simulation time or calculation time, the complexity of the wind power plant model may be reduced by equivalent models, wherein all the wind turbines in the wind power plant are aggregated into a single equivalent wind turbine operating on an equivalent internal electrical network. However, the electrical output obtained from such an equivalent wind turbine will typically not provide a precise calculation of the electrical output of a wind power plant.
Hence, an improved method of calculating an electrical output of a wind power plant comprising a first number of wind turbines would be advantageous.